A. Amal Raj

Synthesis, antimicrobial and antifungal activity of a new class of spiro pyrrolidines.

A new class of spiro pyrrolidines, dispiro[oxindole-cyclohexanone]pyrrolidines, dispiro[oxindole-tetrahydronaphthalen-1-one]pyrrolidines, dispiro[oxindole-arylidene-cyclohexanone]pyrrolidines, dispiro[oxindole-hexahydro-indazole]pyrrolidines, and spiro[butenolide]pyrrolidines, have been screened for their antibacterial and antifungal activity against ten human pathogenic bacteria and four dermatophytic fungi. They were found to have antimicrobial and antifungal activity compounds against various pathogens except Bacillus subtilis. The spiro pyrrolidinines were synthesized by the regioselective 1,3-dipolar cycloaddition reaction of azomethine ylides generated either from isatin and sarcosine or from aziridine. The azomethine ylide so generated reacted with various dipolarophiles such as 2-arylidene-cyclohexanones, 2-arylidene-tetrahydronapthalen-1-ones, 2,6-bis(arylmethylidene)cyclohexanones and 3-arylidene-5-phenyl- butenolides.

A novel entry into a new class of spiroheterocyclic framework: regioselective synthesis of dispiro[oxindole-cyclohexanone]pyrrolidines and dispiro[oxindole-hexahydroindazole]pyrrolidines

Abstract 2,6-Bis(arylmethylidene)cyclohexanones undergo a regioselective 1,3-dipolar cycloaddition reaction with the azomethine ylide derived from isatin and sarcosine by a decarboxylative route affording a series of 1-N-methyl-spiro[2.31]oxindole-spiro[3.211]611-arylmethylidenecyclohexanone-4-aryl-pyrrolidines which were further annulated to give a series of novel 1-N-methyl-spiro[2.31]oxindole-spiro[3.711](311-aryl)Δ111,711a-hexahydro-2H-indazole-4-aryl-pyrrolidines. The structures of which were established by spectroscopic techniques as well as single crystal X-ray analysis.

Synthesis of spiro pyrrolidines via formal [3+2] cycloaddition of unusual enones and cis-3-benzoyl-1-cyclohexyl-2-phenylaziridine

Abstract The synthesis of a new class of spiro[tetrahydronaphthalen-one/butenolide]pyrrolidines has been accomplished by the 1,3-dipolar cycloaddition of azomethine ylide generated by thermal ring opening of cis -3-benzoyl-1-cyclohexyl-2-phenylaziridine with ( E )-2-arylidene-1,2,3,4-tetrahydronaphthalen-1-ones and ( E )-3-arylidene-5-phenyl-Δ 4,5 -butenolides. The structures of the products were confirmed by spectroscopic techniques as well as single crystal X-ray analysis of one of the products.

A Novel Entry into a New Class of Spiro Heterocyclic Framework: A Facile Synthesis of Dispiro[oxindole-1,2,3,4-tetrahydro-naphthalen-1-one]pyrrolidines and Spiro[1,2,3,4-tetrahydro-naphthalen-1-one]pyrrolidines

Abstract 2-Arylidene-1,2,3,4-tetrahydro-naphthalen-1-ones undergo regioselective 1,3-dipolar cycloaddition reaction with the azomethine ylide derived from isatin and sarcosine by decarboxylative route affording a series of 1-N-methyl-spiro[2.31]oxindole-spiro[3.211]111, 211,311,411, -tetrahydro-naphthalen-111-one-4-aryl-pyrrolidines. 2-Arylidene-1,2,3,4-tetrahydro-naphthalen-1-ones also undergo cycloaddition reaction with azomethine ylide derived from paraformaldehyde and sarcosine affording a series of 1-N-methyl-spiro[3.21]11,21,31,41-tetrahydro-naphthalen-11-one-4-aryl-pyrrolidines. The structures of the compounds were established by spectroscopic techniques.

DOUBLE 1,3-DIPOLAR CYCLOADDITION OF 2,6-BIS(ARYLMETHYLIDENE)-CYCLOHEXANONES: A NOVEL ENTRY INTO THE SYNTHESIS OF 2′,6′- BIS-SPIRO(1-N-METHYL-4-ARYL-PYRROLIDINE)CYCLOHEXANONES

ABSTRACT 2-6-Bis(Arylmethylidene)cyclohexanones undergo double 1,3-dipolar cycloaddition reaction with azomethine ylide derived from paraformaldehyde and sarcosine to give bis-spiro-pyrrolidines in good yield. The structures of which were established by different spectroscopic techniques.

Crystal Structure and Conformation of 1, 6-Dioxa[6.5]orthocyclophane-13,16-diene-15-one

1,6-Dioxa [6.5] orthocyclophane-13, 16-diene-15-one[DOCD] crystallizes in triclinic PI¯ space group and the relevant crystal data are: a = 7.577(3) A˚  , b = 10.425(5) A˚  , c = 10.935(5) A˚  , α = 87.89(1)°, β = 78.13(1)°, γ = 78.87(1)°, V = 829.4(6) A˚  3, Z = 2, Dcal = 1.283 Mg/m3. The structure was solved by direct methods and refined by least-squares procedures to a final R-value of 0.0466. The structure is 15-mer whose maximum internal cavity diameter was found to be 6.44 A˚  . The butyl group adopts a zigzag conformation. The crystal structure is stabilized by C– … O types of hydrogen bondings and C–H…π weak interactions in addition to van der Waals forces.